1. Field
The present invention relates to a compound having a xanthene structure, a coloring composition containing a copper compound, an ink for inkjet recording and an inkjet recording method.
2. Description of the Related Art
An inkjet recording method is a method of printing by dispersing an ink droplet and attaching it to a recording medium such as paper as known in the related art. By this printing method, it is possible to print a high-resolution and high-quality image conveniently at a high speed. In particular, in color printing, a technical development has been recently performed for an image forming method which can replace photographs.
In the case of forming a color image by using an inkjet recording method, it is common to use a yellow ink, a magenta ink, a cyan ink and a black ink. Conventionally, water-based inks have been mainly used as these inkjet inks in terms of safety, such as malodor and hazard associated with fire-fighting. These inks are required to fail within suitable ranges in viscosity, surface tension, and the like, to be excellent in nozzle clogging and storage stability, to impart a recording image at a high concentration, and to be excellent in light fastness, ozone fastness, water fastness and moisture fastness.
Such a performance is mostly satisfied by using a water-based ink containing water or a mixture of water and a water-soluble organic solvent as a main solvent. However, characteristics such as color tone, brighteness, light fastness, ozone fastness, water fastness and moisture fastness are influenced considerably by colorants and additives, and various dyes have conventionally been studied.
In a color recording method using a plurality of color inks, uniform characteristics are required to all the constituting ink. Particularly, a magenta dye has a problem in that decolorization by ozone or light (sunlight, fluorescent light and the like) or change in color tone occurs remarkably, compared to other dyes (a cyan dye and a yellow dye). Accordingly, if the ozone fastness or light fastness of the magenta ink is inferior to that of other inks, decolorization of the magenta ink causes the color tone of the whole image of printed matters to be changed, resulting in deteriorating the quality.
Conventionally, an acidic dye having good color strength and high water solubility, such as C. I. Acid Red 52, 249 or 289, is known as a magenta dye for inkjet. However, when such a dye is used alone, clogging of a nozzle hardly occurs due to the high water solubility, but the performances of the ozone fastness, light fastness and moisture fastness are considerably low.
Japanese Patent Application Laid-Open No. H9-157562 (hereinafter JP-A-9-157562) discloses a water-based ink for inkjet recording containing a xanthene derivative colorant having one sulfo group and one sulfonamide group, which is excellent in light fastness.
Further, for a colorant for uses other than an inkjet ink, U.S. Patent Application Laid-Open No. 2006/0230545 (hereinafter US 2006/0230545) discloses a xanthenes derivative having one sulfo group and two sulfonamide groups, or a xanthenes derivative having one carboxyl group and one sulfonyl group having an amino acid group, as a colorant suitably used in a hair dye.
Japanese Patent Application Laid-Open No. 2005-250000 (hereinafter JP-A-2005-250000) and Japanese Patent Application Laid-Open No. H7-179796 (hereinafter JP-A-7-179796) describe a purpose of incorporating a sulfonamide group into a xanthene derivative having one sulfo group, as a colorant suitably used in a toner or a color filter.
However, in JP-A-9-157562, there is no description about a moisture fastness of the ink described therein, which is a performance needed to be used as an inkjet ink. Therefore, there is still room left for review. Also in US 2006/0230545, JP-A-2005-250000, and JP-A-7-179796, there are no description about a purpose of using as the described colorant as an inkjet ink and also about moisture fastness.
An object of the present invention is to provide a compound capable of forming an image which is excellent in moisture fastness as well as hue, print concentration and ozone fastness, a coloring composition containing the compound, an ink for inkjet recording, and an inkjet recording method using the compound.
In order to solve the above-mentioned problems, the present inventors have studied intensively and have found a coloring composition containing a compound represented by Formula (1) as described below. And, the present inventors have found out that it is possible to form an image which is excellent in moisture fastness as well as hue, print concentration and ozone fastness by employing the coloring composition.
That is, the present invention is as follows. Further, in the present specification, “to” indicates a range including the numerical values described before and after “to” as a minimum value and a maximum value, respectively.